Abstract: Techniques to use reservoir capacitors in ADC to supply most of the charge to bit-trial capacitors as bit-trials are performed. An accurate reference voltage source, e.g., a reference buffer circuit, only needs to supply the difference, e.g., an inaccuracy, in the charge supplied by the reservoir capacitors. Instead of having to resettle for each bit-trial, the accurate reference voltage source has only to deliver the initial charge to the reservoir capacitors during acquisition and once more when the ADC is ready to sample onto the residue amplifier. These techniques can ease the demands on the reference buffer circuit and requirement of external decoupling capacitors, for example.

Abstract: An analog-to-digital converter (ADC) circuit comprises a first digital-to-analog (DAC) circuit and a second DAC circuit, wherein the first and second DAC circuits include weighted bit capacitors and reservoir capacitors; a sampling circuit configured to sample a differential input voltage onto the weighted bit capacitors and to sample a reference voltage onto the reservoir capacitors; a comparator circuit operatively coupled to outputs of the first and DAC circuits; and logic circuitry configured to: initiate successive bit trials of weighted bit capacitors to convert the input voltage to a digital value by comparing an output of the first DAC circuit and an output of second DAC circuit using the comparator circuit; and apply charge of the reservoir capacitors to the bit capacitors to reduce the comparator differential input voltage and reduce an error between the input common mode offset and the comparator common mode offset.

Abstract: The present disclosure relates to a voltage reference circuit and a method of providing a voltage reference. The voltage reference circuit uses a switched capacitor arrangement to move charge between capacitors during different phases of operation of the circuit to which the voltage reference is being provided. The circuit being provided with a voltage reference may be an analog-to-digital converter (ADC). A reservoir capacitor is used to supply the reference voltage. During a phase in which no voltage reference is required, charge is shared between the capacitors of the switched capacitor arrangement, in order to boost the charge on the reservoir capacitor. After charge sharing, the reservoir capacitor is topped up with an output from a reference buffer. The reservoir capacitor may then be used again in the next conversion phase.

Abstract: An analog multiplexer may be used for sampling an input voltage that is capable of having a higher voltage level than an upper supply voltage. The analog multiplexer includes a plurality of input switch circuits and a shorting switch circuit. The plurality of input switch circuits include n-type or p-type laterally diffused field effect transistors (NLDFETs or PLDFETs). At least one of the input switch circuits includes a level shifting switch circuit that is able to sample an input voltage that is greater than the upper supply voltage for the multiplexer. A shorting switch circuit, at an output of the multiplexer, includes a capacitively coupled gate drive circuit and is configured to short a first differential output to a second differential output after the input voltage is sampled.

Abstract: A photometry device can include a first LED to emit light to a target in response to a first current through the first LED, a second LED to emit light to the target in response to a second current through the second LED, and an inductor, coupled to the first and second LEDs, to store energy associated with at least one of the first and second currents.

Abstract: During operation of a SAR ADC, several of the MSBs can be preloaded with predetermined bit decisions prior to carrying out bit trials. A system and method can be provided for incrementally preloading the predetermined bit decisions such as to maintain voltages present at comparator inputs within a limited range of acceptable input voltages.

Abstract: An analog multiplexer may be used for sampling an input voltage that is capable of having a higher voltage level than an upper supply voltage. The analog multiplexer includes a plurality of input switch circuits and a shorting switch circuit. The plurality of input switch circuits include n-type or p-type laterally diffused field effect transistors (NLDFETs or PLDFETs). At least one of the input switch circuits includes a level shifting switch circuit that is able to sample an input voltage that is greater than the upper supply voltage for the multiplexer. A shorting switch circuit, at an output of the multiplexer, includes a capacitively coupled gate drive circuit and is configured to short a first differential output to a second differential output after the input voltage is sampled.

Abstract: During operation of a SAR ADC, several of the MSBs can be preloaded with predetermined bit decisions prior to carrying out bit trials. A system and method can be provided for incrementally preloading the predetermined bit decisions such as to maintain voltages present at comparator inputs within a limited range of acceptable input voltages.

Abstract: Various techniques that can provide a capability to background calibrate ADC linearity error, e.g., due to capacitor mismatch drift and other parameter drift, during normal ADC operation in which analog-to-digital signal conversions are ongoing. A method can include grouping capacitors of an ADC into multiple clusters and calibrating under an arbitrary signal condition. To quickly converge the calibration result, the same arbitrary signal can be converted twice, and the capacitor(s) being calibrated can be modulated after first conversion. The difference between the results of the first and second conversions can contain the error information that can be used for calibration, and the signal component can be removed by this process. These techniques can provide improved linearity at 20-bit level and beyond.

Abstract: An analog-to-digital converter (ADC) circuit including error correction circuitry for correcting offset drifts in an ADC, such as a successive approximation register (SAR) ADC. The offset drifts can be reduced, such as by sampling the offset following an analog-to-digital conversion and subsequently providing an error correction signal based on the sampled offset.

Abstract: An analog-to-digital converter (ADC) circuit comprises a first digital-to-analog (DAC) circuit and a second DAC circuit, wherein the first and second DAC circuits include weighted bit capacitors and reservoir capacitors; a sampling circuit configured to sample a differential input voltage onto the weighted bit capacitors and to sample a reference voltage onto the reservoir capacitors; a comparator circuit operatively coupled to outputs of the first and DAC circuits; and logic circuitry configured to: initiate successive bit trials of weighted bit capacitors to convert the input voltage to a digital value by comparing an output of the first DAC circuit and an output of second DAC circuit using the comparator circuit; and apply charge of the reservoir capacitors to the bit capacitors to reduce the comparator differential input voltage and reduce an error between the input common mode offset and the comparator common mode offset.

Abstract: Many electronic circuits rely on the ratio of one component to other components being well defined. Current flow in component can warm the component causing its electrical properties to change, for example the resistance of a resistor may increase due to self-heating as a result of current flow. The present disclosure provides a way to reduce temperature variation between components so as to reduce electrical mismatch between them or the consequences of such mismatch. This is important as even a change of resistance of, for example, 20-50 ppm in a resistor can result in non-linearity exceeding the least significant bit value of a 16 bit digital to analog converter.

Abstract: According to one configuration, a controller controls use of multiple medical devices at a medical site. For example, a first medical device at the medical site is operable to perform one or more tissue ablation operations; a second medical device at the medical site is operable to perform non-ablation operations (such as tissue monitoring operations). The controller implements a control sequence to control switching between different operational modes including a first mode and a second mode. The first mode and corresponding first windows of time enable the first medical device to perform an ablation operation; the second mode and corresponding windows of time disable the first medical device from performing the ablation operation so that the second medical device operates without interference from the first medical device performing the ablation operation.

Abstract: Various examples are directed to configuring a configurable hardware module to perform a measurement of a physical quantity. A configuration manager may receive an indication of the physical quantity and performance factor data describing the measurement of the physical quantity. The configuration manager may generate a hardware configuration of the hardware based at least in part on the indication of the physical quantity and the performance factor data. The hardware configuration may comprise instruction data to configure the hardware module to execute a dynamic measurement of the physical quantity. The configuration manager may also generate configuration data describing the hardware configuration, wherein the configuration data comprises simulation data comprising input parameters for a simulation of the hardware configuration and hardware configuration data for configuring a hardware module to implement at least a portion of the hardware configuration.

Abstract: During operation of a SAR ADC, several of the MSBs can be preloaded with predetermined bit decisions prior to carrying out bit trials. A system and method can be provided for incrementally preloading the predetermined bit decisions such as to maintain voltages present at comparator inputs within a limited range of acceptable input voltages.

Abstract: A voltage sampling circuit is provided that may directly connect a non-zero power supply voltage VDD to switching circuits during input voltage sampling, setting a common mode voltage without using reference voltages produced by a reference voltage generator circuit, and without requiring a common mode buffer circuit. The voltage sampling circuit may be used in an operational amplifier input stage such as for a pipelined ADC circuit, or in a comparator circuit. A SAR ADC circuit is also provided, comprising a control circuit, the voltage sampling circuit, a capacitor array, and a comparator circuit for comparing outputs occurring from charge redistributions. The voltage sampling circuit may enable increased power efficiency, avoid leakage concerns, and increase maximum input voltage swing. Reference plate switches in the voltage sampling circuit may include gate-boosted devices or thicker-oxide I/O devices.

Abstract: An analog-to-digital converter (ADC) system can sample an input voltage for at least a first conversion into a first N1-bit digital value and to use the same input voltage sample for at least a second conversion into a second N2-bit digital value. A difference between a result of the first conversion and a result of the second conversion can be driven toward zero to adjust weights of one or more of the bits to calibrated values for use in one or more subsequent analog-to-digital conversions of subsequent samples of the input voltage. Shuffling, dithering, or the like can help ensure that at least a portion of the decision paths used in the second conversion are different from the decision paths used in the first conversion. Calibration can be performed in the background while the the ADC is converting in a normal mode of operation.

Abstract: Embodiments of the present invention provide a monitoring system that may include a plurality of monitors. Each may have a plurality of input pairs coupled to respective components of a component stack, wherein adjacent monitors each have an input pair coupled to a common component. Embodiments of the present invention provide an integrated circuit that may include a plurality of detectors to locally measure a first group of channels. The integrated circuit may also include a receiver operable to receive a measurement of at least one channel of the first group of channels, and a controller to calculate a correction factor based on the received measurement and a local measurement of the at least one channel and to correct all first group measurements with the correction factor.

Abstract: An interface system between an RDC and a connected resolver dynamically matches an input range of the RDC to the output range of the resolver's output signals. The interface system may include methods and/or apparatuses to determine the amplitude of sinusoidal input signals presented to the RDC by the resolver and to compare the amplitude against high and low threshold values. A gain control signal may be generated, which may be corrected if the detected amplitude either exceeds the high threshold or falls below the low threshold. The gain control signal may be output to a circuit in the RDC or in the resolver that corrects any mismatch that occurs between the RDC input and the resolver output. For example, the gain control signal may control the amplitude of an excitation signal applied to a primary of the resolver or the gain control signal may be applied to an analog to digital converter at the input of the RDC to control its effective input range.

Abstract: A serial protocol and interface for data transmission from a data transmitter 12 to a data receiver 14 where the propagation delay may be up to several clock cycles long and may be varying slowly. The data receiver provides a clock to the data transmitter. A synchronization signal provided by either the receiver or the transmitter initiates a frame of data transmission at a transfer rate controlled by the clock. The synchronization signal coordinates the transmission of a data header followed by a predetermined number of data bits, known as the frame length. The data receiver uses the header bits to determine the times to sample the subsequent data bits. The length of the frame is limited to provide sufficient likelihood the propagation delay line characteristics have not changed enough to cause a bit error. The system resynchronizes at the beginning of each frame.